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Be prepared to be amazed at the life cycle of these parasitoids, the most fascinating parasitoid we've seen yet!

Caterpillar shape as diedwhile preparing to pupate.

A close look shows that it issimply a mass of smaller larvae.

The 'caterpillars' we found were either beige or light green.

The dry larvae are visible when the 'caterpillar' is broken in two.

Microscope view: the larvae are much like chalcid larvae but dry.

Above: these were found and brought inside the office. Thinking that the emerging critters would infect larvae, they were kept sealed in plastic cups to mature and emerge. Lo and behold, we found HOW they come to be and are still amazed at them.Detailed life cycle information is at the bottom of the page.

Although I have not found records of them infecting butterfly eggs, we had one Painted Lady caterpillar that was infected about four years ago; the first time we saw these tiny creatures. Sadly, photos of that larvae have been lost.

Eggs are laid in fresh Lepidoptera eggs and do not finish development until the host is in its larva stage. The parasitoid lays one or two eggs that divide into many eggs, as many as 1,000 or more. These 1,000 eggs may have divided from one single parasitoid egg and are genetically identical. When two eggs are laid in the same host egg, they are usually one male and one female egg. All eggs that divide from a single egg will be the same sex as the original egg.

Once the host has reached a fifth instar, hormones trigger the eggs to hatch. These hormones also cause the host to have additional instars, growing larger and providing more food for the parasitoids. Once the host has created its cocoon to pupate, it dies before it pupates. The body of the host is completely filled with parasitoid larvae. A few days later the parasitoid adults hatch.

As many as 3,055 adults have been recorded as having matured in one host larva. In that larva, 2% died before emerging. Broods commonly exceed 2,000.

Copidosoma studies found that these parasitoids actually increase crop damage due to the increased number of instars and their subsequent demand for more food.

Loopers in the subfamily Plusiinae are the recorded hosts. Both soybean and cabbage loopers are victims of this parasitoid.

Sources:
Personal collecting and photographing these insects - but this can only reveal a tiny fraction of information about these critters. We appreciate those who created the pages linked below.UT ExtensionUFL IFAS Entomology Department